I wish i had a picture of this on the firewall with the prop and and spinner for a better visual This grey backplate seperates the flywheel and prop and also is used to fasten the back of the spinner to. These little bare aluminum shark fin gizmo's are used to fill in the spinner, just behind the propeller blades.
The spinner can be cut real close to the front side of the blades but needs to be left open to the back to fit around the blades. So the spinner infill for behind the blades is fabricated and fastened to the backplate, rather than being integral with the spinner.
You'll spend the good part of a day thinking about and fabricating these little doo dads. With the prop and spinner on the plane methodically drew and cut paper templates then traced them to some .063 AL sheet. Then the process of cutting, shaping to the curve and smoothing out all the edges. Finally they these were riveted to the backplate and i installed platenuts to secure these to the spinner.
